The study included 511 patients who underwent PCI because of angina during 2010-2011 at three Korean hospitals. Clopidogrel-naïve patients received either a loading dose (LD; 600 mg at 2-24 h before the procedure) or routine maintenance therapy (75 mg/day for ≥5 days) plus either a 300-mg reload (RL) or only the maintenance dose (MD).

Elevation of myocardial infarction markers after coronary stenting reflects periprocedural myonecrosis or periprocedural myocardial infarction (PMI), which is associated with an increase in cardiac events and mortality. Thus, we aimed to evaluate various clopidogrel pre-treatment methods for preventing PMI among patients undergoing conventional CAG for stable angina pectoris. The Method of Clopidogrel Pre-treatment Undergoing Conventional Coronary Angiogram in Angina patients (MECCA) study was a prospective, partially randomized, multi-center clinical trial. Between October 2010 and July 2011, 511 patients underwent PCI for angina pectoris at the Korean University Anam Hospital, the Eulji Hospital, and the Hanil General Hospital. Clopidogrel-naïve patients were enrolled to receive a loading dose (the LD group; clopidogrel at 600 mg, usually 2-24 h before the procedure) or routine therapy using daily clopidogrel doses (75 mg/day for ≥5 days). Patients receiving daily doses were randomized to receive either an additional 300-mg reload (the RL group) or no additional loading (the maintenance dose [MD] group). The 600-mg or 75-mg treatment regimens were selected at the physician's discretion. The primary outcome was creatinine kinase myocardial band (CK-MB) levels at several time points. The CK-MB levels were measured at baseline, 8 h, and 24 h, while troponin-I levels were measured at 8 h after the PCI.

Inclusion Criteria:

• Written informed consent and, stable angina pectoris and, at least 1 ischemic evidence below

  1. Treadmil test positive
  2. ST-T change in resting ECG or 24-hour ECG
  3. Regional wall motion abnormality in Echocardiography or cardiac MRI
  4. Myocardial ischemia at MIBI scan
  5. moderate to severe stenosis at coronary CT angiography
  6. chest pain or dyspnea

Exclusion Criteria:

• AST or ALT > 3 times upper normal limits
• Serum creatinine > 2.0 mg/dL
• chronic malaborption status (disorder or operation)
• planned surgery within 1 year
• pregnancy or breast-feeding patients
• life expectancy < 1 year